Invasive alien plant species in China: regional distribution patterns

Plant invasions have been attracting increasing attention from ecologists because of their worldwide environmental impacts and huge economic costs. Research on the characteristics of the recipient regions is essential for understanding the process of plant invasion. However, few previous studies on invasibility of habitats include social factors, although human activities are critical in the process of plant invasion. China is a vast country with high plant species diversity and a long history of introduction of exotic plant species and is particularly vulnerable to invasive plant species. Alien plant species are widespread in the country. Therefore, the study of invasive plants in China is urgent in practice and theoretically important for developing invasion ecology. For the present study, 126 species were selected to represent the major invasive plant species in China. We then collected data on their species richness in 31 provincial administrative units of China and performed Spearman rank correlations between species richness and possible natural and socio‐economic factors. We found that socio‐economic factors, such as human density and GDP, correlated positively with the species richness of invasive plants in China. In conjunction with the natural and socio‐economic correlations in the study of regional distribution pattern of the major invasive plants, we discussed the factors influencing the regional distribution pattern of the major invasive plants in China. We suggest that native plant species richness was mainly determined by the natural conditions of the regions, while invasive species richness was influenced by natural conditions and human disturbance together.     

华根霉固态与液态培养产胞外蛋白的比较蛋白质组学分析

【目的】考察固态和液态两种培养方式对丝状真菌华根霉(Rhizopus chinensis)CCTCC M201021产胞外蛋白的影响,以加深对微生物固、液态培养特异性产酶的认识。【方法】利用成分相同的培养基对华根霉分别进行平板固态培养和液态培养,提取华根霉所产胞外蛋白,采用二维凝胶电泳(2-DE)结合质谱分析,分离鉴定差异蛋白。【结果】固态培养下华根霉所产胞外蛋白的蛋白酶活性是液态培养的9.2倍。胞外蛋白质组数据分析表明,华根霉固态和液态培养所产胞外蛋白存在显著差异,其中约70%是固态和液态培养下各自产生的特有蛋白。质谱鉴定进一步表明,固、液态培养对华根霉产胞外蛋白的种类和表达量都有显著影响,其中水解酶类所占比例较大,主要是与蛋白质降解相关的蛋白。【结论】固态和液态不同培养方式影响了华根霉产胞外蛋白的组成,有些基因只在特定培养方式下表达。固态培养下华根霉产胞外蛋白酶种类相对更多以及大部分蛋白酶的上调表达,可能是固态培养下胞外蛋白酶活性很高的原因。研究结果提示需要注意固液态不同培养方式下丝状真菌胞外酶的筛选和生产可能存在的不一致性。     

The Kv2.1 channels mediate neuronal apoptosis induced by excitotoxicity

Chronic loss of intracellular K⁺ can induce neuronal apoptosis in pathological conditions. However, the mechanism by which the K⁺ channels are regulated in this process remains largely unknown. Here, we report that the increased membrane expression of Kv2.1 proteins in cortical neurons deprived of serum, a condition known to induce K⁺ loss, promotes neuronal apoptosis. The increase in I _K current density and apoptosis in the neurons deprived of serum were inhibited by a dominant negative form of Kv2.1 and MK801, an antagonist to NMDA receptors. The membrane level of Kv2.1 and its interaction with SNAP25 were increased, whereas the Kv2.1 phosphorylation was inhibited in the neurons deprived of serum. Botulinum neurotoxin, an agent known to prevent formation of soluble N -ethylmaleimide-sensitive factor attachment protein receptor complex, suppressed the increase in I _K current density. Together, these results suggest that NMDA receptor-dependent Kv2.1 membrane translocation is regulated by a soluble N -ethylmaleimide-sensitive factor attachment protein receptor-dependent vesicular trafficking mechanism and is responsible for neuronal cell death induced by chronic loss of K⁺.     

小球藻中类胡萝卜素类化合物的高效液相色谱分离条件的优化

采用超声破碎法和甲醇:二氯乙烷=2:1(v/v)溶剂来萃取小球藻中类胡萝卜素类化合物.分别采用了3种不同的色谱分离方法,最后确定小球藻中类胡萝卜素类化合物的最优色谱分离条件为甲醇(A):乙氰(B)=90:10(v/v),柱温为室温,流速1ml/min.用ZOBAX SB-C18色谱柱和ZOBAX Eclipse plus C18色谱柱进行分离试验时发现,ZOBAX Eclipse plus C18色谱柱的分离效果良好.最后确定小球藻中叶黄素含量为2.312mg/g.     

内蒙古道虎沟中侏罗世假古蝉属化石(同翅目,古蝉科)

描述古蝉科化石3新种,即多点假古蝉Pseudocossus punctulosus sp.nov.,美丽假古蝉P.bellus sp.nov.,弯脉假古蝉P.ancylivenius sp.nov..所有标本均采自内蒙古宁城道虎沟中侏罗世九龙山组,其中2个新种保存有完整的臀区.模式标本保存在首都师范大学生命科学学院.     

CTSB promotes porcine preadipocytes differentiation by degrading fibronectin and attenuating the Wnt/β-catenin signaling pathway

The process of preadipocytes differentiation plays a vital role in adipose tissue expansion and many factors are involved in this event. Cathepsin B (CTSB), secreted from lysosome, has been reported in regulating a variety of physiological processes. In this study, we demonstrated CTSB promotes lipid accumulation and adipogenic genes expression in porcine primary preadipocytes by degrading fibronectin (Fn), a key component of extracellular matrix. Lithium chloride (LiCl) is an activator of Wnt/β-catenin signaling through stabilizing β-catenin. We found that CTSB can relieve the anti-adipogenic effects of LiCl, indicating that CTSB could impact Wnt/β-catenin signaling pathway. Interestingly, Fn is an important target gene of Wnt/β-catenin. So we considered that CTSB promote preadipocytes differentiation by suppressing these two pathways.     

Blockade of L-type voltage-gated Ca channel inhibits ischemia-induced neurogenesis by down-regulating iNOS expression in adult mouse

Neurogenesis in the adult mammalian hippocampus may contribute to repairing the brain after injury. The signals that regulate neurogenesis in the dentate gyrus following ischemic stroke insult are not well known. We have previously reported that inducible nitric oxide synthase (iNOS) expression is necessary for ischemia-stimulated neurogenesis in the adult dentate gyrus. Here, we show that mice subjected to 90 min of middle cerebral artery occlusion (MCAO) significantly increased the number of new neurons and up-regulated iNOS expression in the dentate gyrus. Blockade of the L-type voltage-gated Ca(2+) channel (L-VGCC) prevented neurogenesis in the dentate gyrus and subventricular zone (SVZ), and down-regulated iNOS expression in the dentate gyrus after cerebral ischemia. This study suggests that Ca(2+) influx through L-VGCC is involved in ischemia-induced neurogenesis by up-regulating iNOS expression.     

人白介素6受体基因在痘苗病毒载体系统中的表达

人ＩＬ－６受体是一个在各种细胞上广泛表达的跨膜糖蛋白分子,是ＩＬ－６发挥细胞效应所必需的。本文通过将ＩＬ－６ＲｃＤＮＡ重组到痘苗病毒的ＴＫ基因中构建成重组痘苗病毒ＶＩＬ６Ｒ。细胞原位杂交和ＡＰＡＡＰ染色结果表明,感染ＶＩＬ６Ｒ后的Ｖｅｒｏ细胞中,ＩＬ－６Ｒ在ｍＲＮＡ和蛋白水平上均呈现较强的表达。Ｗｅｓｔｅｒｎｂｌｏｔ分析所表达的分子量为８０ｋＤ,表明所表达的产物是糖基化的。ＩＬ－６结合试验表明,表达的膜ＩＬ－６Ｒ能够结合ｒＩＬ－６,说明它是有功能的。利用ＶＩＬ６Ｒ免疫小鼠后,能够刺激较强的抗体产生。从而为进一步研究ＩＬ－６Ｒ的信号传导和构效关系提供了基础。